1. Field of the Technology
The present disclosure relates generally to map version control techniques for updating the use of network-maintained map data sets for mobile communication devices operating in wireless communication networks.
2. Description of the Related Art
Mapping techniques may utilize network-maintained map data sets stored in a network database and managed by one or more network servers for mobile communication devices. Initially, a mobile communication device must request and retrieve the map data from the network database over the wireless communication network and store the map data in a memory cache. The processor subsequently utilizes the map data in its cache to render maps in the visual display of the device. Subsequently, any map data not found within the cache (typically the case when the location or region of the map substantially changes) needs to be similarly requested and retrieved from the network database.
However, the network database may be updated over time with one or more different versions of map data. This updating may be performed regularly over time when new or alternative map information is made available; the updates may be important corrections to errors or updated visual or textual features.
If an alternative version of the map data is made available to all mobile communication devices in the wireless communication network at substantially the same time, and the alternative version replaces the previous version in the network database, then the mobile communication devices may render maps which are visually inconsistent due to the inconsistencies between the previous version of map data in its cache and the updates it receives. If the alternative version of the map data is made available and required to be utilized in full by the mobile communication devices (i.e. full download to replace all map data in its cache), then the wireless communication network would be overburdened with high volumes of map data traffic at the same time. Also, a mobile communication device would perhaps be unwittingly utilizing bandwidth that it might not have wanted to utilize, and may undesirably require the end user of the device to bear the costs of the extra bandwidth usage.
Accordingly, there is a need for map version control methods and apparatus for updating the use of network-maintained map data sets, especially for use in mobile communication devices which operate in wireless communication networks.